This invention relates to the field of contrast control for liquid crystal displays and more particularly to apparatus for adjusting the contrast control voltage of a liquid crystal display to compensate for ambient temperature effects. Liquid crystal displays are generally driven by a driving voltage VDD-VLCD, where VDD is a supply voltage which is applied uniformly to all cells of the display, and VLCD is a contrast control voltage which is selectively switched only to predetermined cells. In general the visual contrast between a selected cell and a non-selected cell varies with viewing angle, incident lighting level and the level of the driving voltage. For any combination of incident lighting level and viewing angle, there is a driving voltage which produces the optimum contrast. Unfortunately, the optimum driving voltage changes with ambient temperature. This variation of optimal driving voltage with temperature is well known, and numerous schemes have been devised for introducing automatic corrections. However, prior art devices are often times inaccurate. Those which have produced satisfactory accuracy are generally complicated and expensive. There is a need for a simplified and effective device for automatically correcting the driving voltage to a liquid crystal display to compensate for the effect of temperature on the observed contrast.